This invention relates to a mineral mining pick (which term, as is generally acknowledged in the art, includes a pick for rock mining and for road planing) and a pick holder by which the pick is operatively retained and which is likely to be in the form of a socketed block or box on or in a driven drum of a mining machine but may be the drum itself.
It is conventional practice in pick and holder combinations to provide retaining means by which the pick is held in the holder during use but which can be manually disengaged to release the pick from the holder for servicing or replacement. The usual form of pick and holder combinations has a shank of the pick received in a complementary socket in the holder and generally the retaining means comprises a spring or similarly loaded pin carried by either the shank or the holder to be biased into engagement with a recess in the holder or shank as the case may be to provide the necessary retention; release of the pin to permit removal of the pick is achieved by displacing the pin against its biasing sufficient to clear the recess. A well known example of such retaining means is referred to in the art as the "stud-lock", an example of which is disclosed in GB Specification No. 1,144,434 while an alternative form of retaining means is disclosed in GB Specification No. 1,170,979. The machining and fitting necessary to provide the retaining means between the pick and its holder contributes considerably towards the manufacturing costs of the pick and holder and the wear and tear to which the retaining means is subjected in use usually necessitates their frequent servicing and replacement. Furthermore, with the conventional form of retaining means it is usually considered impractical or inconvenient to fit replacement parts on site and often the retaining effect which is provided is far greater than that considered necessary for safety (this together with poorly conceived principles of construction and/or undesirable location of the retaining means frequently results in difficulties being encountered for release of the pick). It is an object of the present invention to provide the combination of a pick and a pick holder by which the aforementioned disadvantages of conventional means for retaining the pick in the holder are alleviated.